itch.io

Talk to the life guard in the entrance of the beach, he is going to mention something about a guys that does massages, go to the resting place of the beach and there is a chance that the event happen, the girls will say something about feeling a strange presence.

If it helps, in the LCOTH discord there is a guide for all the scenes of each area, so you only search "beach" and you will find all the scenes on the beach.